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      1 /*	$NetBSD: bn_mp_submod.c,v 1.2 2017/01/28 21:31:47 christos Exp $	*/
      2 
      3 #include <tommath.h>
      4 #ifdef BN_MP_SUBMOD_C
      5 /* LibTomMath, multiple-precision integer library -- Tom St Denis
      6  *
      7  * LibTomMath is a library that provides multiple-precision
      8  * integer arithmetic as well as number theoretic functionality.
      9  *
     10  * The library was designed directly after the MPI library by
     11  * Michael Fromberger but has been written from scratch with
     12  * additional optimizations in place.
     13  *
     14  * The library is free for all purposes without any express
     15  * guarantee it works.
     16  *
     17  * Tom St Denis, tomstdenis (at) gmail.com, http://libtom.org
     18  */
     19 
     20 /* d = a - b (mod c) */
     21 int
     22 mp_submod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
     23 {
     24   int     res;
     25   mp_int  t;
     26 
     27 
     28   if ((res = mp_init (&t)) != MP_OKAY) {
     29     return res;
     30   }
     31 
     32   if ((res = mp_sub (a, b, &t)) != MP_OKAY) {
     33     mp_clear (&t);
     34     return res;
     35   }
     36   res = mp_mod (&t, c, d);
     37   mp_clear (&t);
     38   return res;
     39 }
     40 #endif
     41 
     42 /* Source: /cvs/libtom/libtommath/bn_mp_submod.c,v  */
     43 /* Revision: 1.4  */
     44 /* Date: 2006/12/28 01:25:13  */
     45